Rotary burnishing machine for formed metal articles



Jan. 25, 1955 C. C. KINKER ETAL 2,700,254

ROTARY BURNTSHTNG MACHINE FOR EORMED METAL ARTICLES Filed May 15, 1953 v 2 sheets-sheet 2 Cyafen C. fmker dames Maffay/L1 United States Patent ,F

ROTARY BURNISHING MACHINE FOR FORIVIED METAL ARTICLES Clarence C. Kinker, Manitou Beach, Mich., and James I. Murtagh, Toledo, Ohio, assignors to Gerity-Michigan Corporation, Adrian, Mich., a corporation of Michigan Application May 15, 1953, Serial No. 355,256

1 Claim. (Cl. 5117) This invention relates to the burnishing of metal articles, and particularly to means for accomplishing this in a rapid, simple and eicient manner.

Attempts have been made to burnish metal articles by rapidly revolving or moving the articles through a liquidcontaining in suspension an abrasive material; also by suspending the articles in such a burnishing liquid and forcefully directing the ow of the liquid thereagainst, but these methods have been unsuccessful due not only to slowness of operation but also to ineflicient and unsatisfactory quality of the work performed.

An object of the invention is the provision of a new and improved article burnishing machine wherein articles are rapidly revolved in a cylindrical path while submerged in a liquid containing in suspension an abrasive material and during such movement and submersion subjecting the articles to a mechanical rubbing or abrading action, whereby a drapid and efcient burnishing of the articles is ob taine Other objects and advantages of the invention will be apparent from the following detailed description and from the accompanying 'drawings illustrating one embodiment of a means for practicing the same, in which- Fig. 1 is a sectional elevation of a machine embodying the invention with work articles in burnishing position therein;

dFig. 2 is an enlarged section on the line 2--2 in Fig. 1; an

Fig. 3 is a section on the line 3-3 in Fig. 1.

v The invention consists broadly in providing a container with a cylindrical vertical wall that is lined with a material having a multiplicity of pliant substantially radial abrading or rubbing projections on its inner surface, and rapidly revolving either the articles to be burnished in said container in abrading or rubbing engagement with said projection and in submerged relation to the liquid, or rapidly revolving the container with respect to the article.

ln the illustrated embodiment of the invention, designates a base frame having uprights 11 at opposite sides and these are connected at their upper ends by a top structure 12. An open top cylindrical container 14 is mounted in the lower portion of the frame on the base 10 and is adapted to be closed at its top by a removable cover 15. The cylindrical side wall of the container is lined with one or more strips of yielding pliant material such as soft rubber, which strips extend entirely around the inner surface of the container wall and are provided on their exposed inner surfaces with a multiplicity of pliant projections 17 intended to have frictional rubbing or abrading engagement with the work-pieces being burnished, as hereinafter described. In the present instance, two vertically spaced abrading strips 16 are employed, and each pro vides an annular set of said projections.

Centrally on the bottom of the container 14 is a pedestal bearing 18 in which the lower end of a vertical shaft 19 is journaled. This shaft extends up through the cover to near the top of the frame where it is coupled to the shaft 20 that is journaled in a bearing 21 located centrally on the top frame structure 12. A pulley 22 is fixed to the upper end of the shaft 20 and is connected by a belt 23 to the drive pulley 24 of an electric motor 25 that is attached to the upper ends of certain of the uprights 11.

A sleeve 28 is mounted on the shaft 19 for rotation therewith and axial reciprocatory movements thereon and is of a length to extend from near the lower end of the shaft 19 to and through the container cover 15, and may ice be raised from such position a distance which is preferably substantially equal to the height of the container. The sleeve 28 extends through a bearing 29 on the cover 15. A cross-bar 30 is mounted on the cover 15 and has its ends' projecting radially therefrom and entering vertical guide spaces 31 between uprights 11 at the respective sides of the frame.

One or more series of circumferentially spaced radial arms 32 are fixed at their inner ends to respective collars 33 on the shaft 28 so as to turn in the container with the sleeve. In the present instance, these arms are six in number and equidistantly spaced, and a series is provided for each liner strip 16 between its upper and lower edges.v Attached to the outer end of each arm is a holder or backing plate 34 adapted to carry at its outer side a work-piece A to be burnished by frictional engagement with the vbuifrng or abrading projections 17 whenv the sleeve is rotated. The projections 17 stand in the path of revoluble movements of the work-pieces whereby they are bent over by the rubbing action of the workpieces and are also caused to conform to irregularities in the surfaces with which they engage. It will be apparent that the fixtures 34 can be adapted to receive various sizes and shapes of work-pieces which latter may all be similar or may be different, depending on the production operations involved.

A suitable abrasive or burnishing material is suspended in a liquid 36 in the container and this liquid is of sufficient depth to completely cover articles being burnished so that they revolve in completely submerged relation in the liquid. The abrasive may consist in finely divided alumina and silica particles, and lubricants and wetting agents may be incorporated in the liquid. If desired relativelysoft abradants such as cork particles may be intermixed. v

It is apparent that during revolution of the articles in the container, the suspended burnishing or abrasive material is forcefully rubbed against, and into crevices in, the exposed surfaces of the articles and a polishing thereof effected in a rapid, economical and eiiicient manner.

In some instances, where the shape of the work-pieces makes it desirable, rotation is established iirst in one direction and then in the other so that an equal finish is imparted to all areas of the work.

When a burnishing operation has been completed, the driving of the shaft is stopped and the sleeve 28 with its arms 32 and the carried work-pieces A, as well as .the cover 15, are raised above the container to a position suitable for a removal of the burnished articles from the arms 32 and the replacing thereof by others. The sleeve is then again lowered to submerge the arms 32 and articles A carried thereby in the burnishing liquid and is rapidly rotated to effect burnishing of the new group of workpieces.

The weight of the sleeve and parts carried thereby is counterbalanced by a weight 38 which is connected by one or more cables 39, guided by sheaves 40, to a collar 41 carried by the cover 15 between the cross members 30. The sleeve 28 projectsbeyond and is shouldered over the collar 41, being rotatably mounted with respect thereto. Thus as the collar 41 and cover 15 are raised the sleeve 28 and the radial work carrying arms 32 will also be raised out of the tank.

We wish it understood that our invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modiiications and changes without departing from the spirit of the claim.

What we claim is:

In a machine for burnishing metal articles, a container having a vertically disposed cylindrical side wall, a lining for said wall having pliant article rubbing projections on its inner surface, a liquid in the container having a suspended burnishing material therein, a vertical drive shaft centered in said container and extending above the container, means mounting said shaft for rotation in the container, a sleeve mounted on said shaft for rotation therewith and axial shifting movements thereon into and out of the container, means for driving said shaft and sleeve, arms turnable with and projecting outward from said sleeve, means at the outer ends of the arms for carrying articles to be burnished with the articles submerged Patented Jan. 25, 1955.V

9 4 A ..5 l in saicl`r liquid and in rubbing engagement with said pro- References Cited in the le of this patent jetonsix/hvenA the sleeveisw loxazeredtoL position the arms. l Y, within the container and the, shaft is rotated, said arms UNITED STATES PATENTS and articles carried thereby being shiftable on the shaft 981,417 Halsey et al I an. 10, 1911 torta position: aboveV the. container to,- failitate removal 5 2,425,640 Pruitt et al Aug. 12, 1947 and, replaeement: of the articles, 2,494,733 Whitehead r Jan. 17, 1950 vFOREIGN PATENTS 96,210V swit;er1and sept. 16, 1922 

